Revision of Previously Reported Financial Information Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill	$ 27,908	$ 23,409
Total assets	4,241,114	4,026,428
Other non-current liabilities	86,265	113,242
Total liabilities	2,901,054	2,808,892
Accumulated deficit	(403,820)	(467,747)
Total Amkor stockholders’ equity	1,321,048	1,200,286
Total equity	1,340,060	1,217,536	$ 1,197,017	$ 1,129,449
Total liabilities and equity	$ 4,241,114	4,026,428
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill		19,443
Total assets		4,022,462
Other non-current liabilities		101,679
Total liabilities		2,797,329
Accumulated deficit		(460,150)
Total Amkor stockholders’ equity		1,207,883
Total equity		1,225,133
Total liabilities and equity		4,022,462
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill		3,966
Total assets		3,966
Other non-current liabilities		11,563
Total liabilities		11,563
Accumulated deficit		(7,597)
Total Amkor stockholders’ equity		(7,597)
Total equity		(7,597)
Total liabilities and equity		$ 3,966